Weird Linq to Sql error - retrieving too many fields

Question

Hi folks,

I've got a pretty simple Linq to Sql statement that (on he surface) is working fine. When I check the sql code that it generates, it's trying to retrieve all of the table fields instead of the fields that I just request. Is this normal practice?

here's some psedo code for the linq to sql query :-

var result = (from q in db.Foos
              where blah blah blah
              orderby more blah
              select new ResultThingy
              {
                  A = q.A, // int
                  B = q.B, // string
                  C = q.Bar.A // int
                  D = q.Bar.B // string
              })
              .Take(5)
              .ToList();

Now, it's retreiving all the values from table Bar ... (and a few other fields).

Is this normal practice? Notice how each property in the ResultThingy class is a simple type?

Hmmm... thoughts? I'm really confused over this.

Answer 1

This is normal (after looking at your code carefully).

As you are using a .NET type (not an entity), Linq2SQL has to extract everything up to the last select.

The get around this, use an anonymous object instead.

IOW: select new { q.A, q.B, C = q.Bar.A, D = q.Bar.B }